Electric heater.



w. s. HADAWAY, IR.

ELECTRIC HEATER.

APPLICATION FILED MAR. 29, I9I3.

LMAQQS @muted Aug. 17, 1915.

Fgzj. 554,7

WILLIAM S. HADAWAY, JR., F NEW ROCHELLE, NEW 'YORK ELECTRIC HEATER.

Application tiled Iaroh 29, 1913. Serial No. 757,653.

T0 au whom it may concern:

Be it known that I, W1LLIAM S. HADAWAY, Jr., a citizen of the United States, residing at New Rochelle, in the county of Westchester and State of New York, have invented new and useful Improvements in Electric Heaters, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawing, forming a 'part of this specification.

My invention relates to improvements in electric heaters.

In the manufacture of electric heating appliances, one'of the mostimportant problems to be dealt with is that of securing the resistor in close heat-conducting relation with the body having thereon the heating surface or working face, so as to insure high thermal efficiency. While use may be made of various constructions which are apparently satisfactory for the purpose from purely a mechanical standpoint, the development of the art has been such as to impose limitations along many lines: for example, compactness of structure, simplicity of design, ease of assembling and adaptability of standard forms to varying structural requirements, are allvdemanded in addition to the primary requirement of efficiency. Accordingly, many designs which satisfactorily fulfil one set of requirements are not as satisfactory with respect to the other requirements, and in many devices where the desired efliciency has apparently been attained in conjunction with a satisfactory compromise with respect to structural features, the efficiency has not been maintained throughout a long continued use of the appliances. To attain the various necessary advantages with the minimum of undesirable features, I have developed heretofore, and have covv ered in numerous co-pending applications,

a variety of heating appliances wherein the resistor is carried and protected by, and thoroughly. insulated from, a sheet metal carrier, the latter being directly welded electrically to the heated body. This construction has unusual adaptability and has proven very successful and highly eiiicient. There are some instances, however, where, because of conditions imposed by the particular construction under consideration, ,it is not desirable or feasible to carry out a welding operation, electrically or otherwise. To meet such special cases as this, I provide Specication of Letters Patent.

Patented Aug. 17, 1915.

improvedl means for securing the resistor to the body to be heated in such a maimer as to secure many of the important advantages heretofore attained without necessarily resorting to electric welding, this constituting, generally speaking, one of the more important objects of the invention. y

A nother of the m'ore important objects of the lnvention is to provide a structure where- 1n the heating surface may be made of metal which is particularly adapted for certaln classes of work, cast iron, for example, and wherein the heat is conducted thereto by a different metal of better heat-conducting properties, such for example, as rolledsteel or wrought iron.

As contributory toward carrying out the general objects above stated, my invention has also the following objects: to provide a construction in which the carrier for the resistor may be secured directly against the surface of the heating plate without machining the latter; to provide a construction in which a heating surface may be readily obtained by casting metal about portions of the carrier to secure the same in place; to provide a heater in which the metal of good heat conductivity, which is employed to conduct heat to the outer heating plate, is substantially integral with the latter.

In the accompanying drawings I have illustrated more or less diagrammatically, different forms of the invention. These forms are intended as suggestive of various dierent embodiments which the invention may assume in practice, and accordingly, said invention is not necessarily limited to the details of the devices disclosed.

In the drawings Figure l is a sectional elevation of a general form of heater wherein a sheet metal carrier for a resistor is secured between a good heat-conducting plate and a metal shoe cast about said plate. Fig. 2 is a sectional elevation thereof showing the resistor and insulation secured in place by said carrier. Fig. 3 is a top plan view thereof. Fig. 4 is a sectional elevation of a heater construction, wherein a cast iron plate or shoe is cast about a good heat-conducting plate, to which latter the resistor carrier may be welded. Fig. 5 is a sectional eleval ing surface.

single cast iron heating plate cast about the same. Fig. 8 is a sectional elevation of a construction wherein a plurality of resistor carriers are welded to a single plate about which-iron is cast to form the desired heat- Fig. 9 is a top plan view of the base of a laundry iron, the base plate being cast around the carrier. Fig. 10 is Na sectionalelevation thereof illustrating some ofthe steps in the assembling. Fig. 11 is a similar sectional elevation but of the assembled parts. Fig. 12 is a sectional elevation of a modified construction of cast metal heating plate, with the resistor removed. F ig. 13 is a sectional elevation of the completed construction.

The disclosure in Figs. 1, 2 and 3 is somewhat diagrammatic. In these, figuresa bar or'ballast plate l, of good heat-conducting properties, is employed. This plate may be made of steel, wrought iron, or other suitable material. A sheet metal channel 2 is provided, which fits over said plate l with its vertical flanges extending above said plate. Iron, or other suitable metal, is then cast about the structure thus formed, whereby an outer cast plate`or shoe 3 is formed, the surface 4 of which may constitute the heating surface or working face. The metal is cast, of course in a suitable mold, not shown. Said metal shrinks in cooling, and thereby firmly holds the sheet metal carrier in place between itself and `the steel or wrought iron plate 1. The elements 1, 2 and 3 are thereby held together in good heat-conducting relation and constitute substantially an integral construction.

The electrical resistance element or resistor, may assume any desired form. I have illustrated as the preferred construction a, thin, slotted metallic ribbon 5, which is placed on the steel or wrought iron plate 1 and suitably insulated by strips of mica 6 and 7 placed above and below the same. A sheet metal cover plate 8 may then be placed over the upper sheet of mica and the projecting flanges of the sheet metal channel 2 bent down over said cover plate to firmly hold the various parts in place and to secure them in good heat-conducting relation with the supporting structure. Since the -plate 1 consists of metal `of good heat conductivity, the heat is conducted readily from the resistor to the cast iron plate 3. Said cast iron, although not as good a heat conductor as steel or wrought iron, or other materials which might be employed, nevertheless lends itself readily to the formation of any desired shape or contour, in that it may be cast in a mold. The thickness of the cast iron plate is preferably much less than that of the plate 1, whereby, although its heat conductivity is not as good as that of said plate 1, this slight difference in conductivity is of no practical importance. The use of a sheet metal cover plate 8, although desirable in many cases, is not essential, andherce may be omitted where the conditions warrant.

In Figs. 4, 5 and 6, I have illustrated a construction wherein the cast metal plate l9 is cast directly about the steel plate 10, land hence grips the same firmly. The two plates constitute practically an integral unitary construction. A sheet metal channel 11 is electrically 'welded to the plate 10, in insttnces where the 'welding operation is feas- 1 e. iron or other suitable material, is particularly adapted `fora firm weld, and accordingly, by the employment of the combined steel and cast iron plates, a resistor carrier may be welded in place whereas it could not be if the entire structure were of cast iron, cast iron being unsnited for such welding operations. Within the carrier 11, a suitable resistorl may be secured in a manner similar to that previously described, the arrangement being shown in Figs. 5 and 6.

In the construction shown in Figs. l, 2 and 3, it will be seen that the resistor carrier is, to all intents and purposes, integrally un'ited to the structureof the heater, while at the same time, it is not welded thereto. This construction, therefore, is particularly applicable where welding is not desirable or advisable. In the construction shown in Figs. 4, 5 and 6, electric Welding is employed to integrally unite the carrier to the heater structure, but use is made of the good heat-conducting properties of steel or wrought iron combined with the advantages ofacast iron working face'. A further advantage in the use of steel or wrought iron is that the surface thereof requires no machining prior to the securing of the resistor in place. These two more or less diagrammatic embodiments of the invention illustrate, generally speaking, the two main phases thereof. One phase is the Securing of the resistor carrier in such a manner that it is integrally united to the heater structure without welding, and the other phase is the employment in a heater structure, of different metals one of which gives rthe advantage of good heat conductivity and the other of which gives the advantage of a good working face; said latter phase of the in- Vention being independent of the method of securing the resistor in place.

In Fig. 7, I have shown how a larger area may be heated by a construction analogous to that shown in Figs. 1, 2 and 3. In this figure, a plurality of steel or wrought iron plates 12 are held in a cast iron structure 13, the carriers 14 being similar to those already described.

In Fig. 8, I have shown a construction wherein a large area may be heated4 by a combination of elements analogous to that shown in Figs. 4, 5 and 6. In this figure, a

Said plate, being of steel, wrought' constitutes the working surface.

closed above, the carrier has the form of a channel, it may be otherwise formed, certain modifications being hereinafterl suggested. Said carrier may also be perforated prior to the casting operation, whereby it is more securely locked in place by the cast iron which fiows into and fills the openings therein.

In the above disclosures, the heaters, for the purpose of simplifying the descriptions, have the form of a simple rectangle, the figures being, as previously stated, more or less diagrammatic. The methods of construction disclosed herein, however, are applicable to a great variety of heater struc-A tures. For the purpose of illustrating one of the many applications of the broad features thereof, I have shown in Figs. 9 to 13 inclusive, a laundry iron structure. Said laundry iron illustrates only one of a great range of applications of the above described principles of construction. The carrier, as shown in Fig. 10, comprises a sheet metal angle 18, having a smaller angle 19 overlapping the same, so as to form a channel. Said channel is curved to conform to the outline; of the laundry iron. A metal plate 20, constructed preferably of rolled'steel or wrought iron, is fitted within the channel. Said plate may be stamped out of the original metal, or formed in various other ways. It isfitted snugly within the channel, the two are placed in a mold, and a face 21 is cast about them, the outer surface of which The cast iron seals the unit carrier securely to the steel plate, so that electric welding or mechanical fastening means -are not needed. 'lhe steel plate supports the carrier during the casting, and the cooling of the iron causes a shrinkage which binds the carrier tightly between the steel plate and the castiron plate. The outer surface of the iron is chilled during the casting so as to give a hard surface, which is very desirable for ironing. The rapid chilling is due, in part, to the quick absorption of heat by the steel plate.- Said steel plate requires no machining and, accordingly, the resistor 22, with suitable strips of mica 23, 24', may be placed directly thereon and firmly held in position in good heat-conducting relation by bending over the flanges of the channel members 18 and '19. A pressure plate 25 may be placed over the mica and beneath the bent over flanges, as in the prior constructions described, the finished structure ,being shown in Fig. 11.

In addition to theabove enumerated advantages of the cast iron heating plate for securing the carrier in position, Ithe-further advantage may be emphasized that said plate may be cast to any suitable configuration; and, furthermore, different elements may be embedded in the cast iron and thereby secured in position without machining. For example, in the case of the laundry iron under consideration, a .screw threaded stud 26 may be cast in position, thereby providing a ready means for attaching the upper parts of the iron to the lower. As said upper parts form no part of the present invention, they are not illustrated yor described herein. Suitable details are disclosed, however, in my co-pending application, N o. 740,365, said application showing how a ballastlplate, cover and handle may be readily secured to the base of an iron bv the use of a single stud, such as illustrated herein.

In Figs'. 12 and 18, I have illustrated a construction quite similar to'that just described, eXcept that the carrier, instead of having the cross section of a channel, consists simply of a pair of angles 27, the horizontal flanges ofwhich are very short, being long enough, however, to embrace the lower edge of the steel plate 20 and thereby secure a firm hold thereon. Said angles are bent down over the heater unit in the manner previously described, the completed structure being shown in Fig. 13. In order to increase the security of the engagement between the sheet metal carrier and the structure cast about the same, the sheet metal may be provided with a plurality of holes, which are filled by said cast metal to insure a positive engagement. Although no screw threaded stud is illustrated in these two iigures, such a stud may, of course, be cast in, if desired, or the cast plate may be drilled ,and tapped and the stud screwed in, al-

though the former method is, of course, the simpler. A

The advantage of the above described cast-in construction is that the heat-conducting properties of the steel plate are very good, and accordingly, the heat is conducted rapidly from the resistors, which may, therefore, be worked at a high temperature in ironing. The cast iron shoe forms a very desirable ironing surface.` In the case of the iron illustrated, the resistor is held in place without electric welding.

In view of the above description, it will be apparent that the invention is adapted for a wide range of usefulness and is in no wise limited to the few embodiments selected for illustrating the main features thereof. Accordingly, I do not desire to limit myself to the details of the present disclosures, except where limitations appear in the appended claims. I do, however, desire to cover as falling within the scope of the in- 1. An electric heater comprising a casty metal structure, a plate of better heat-conducting properties than said cast metal embedded therein but having an exposed area, and a resistor firmly secured to said area, whereby the heat from said resistor is conducted through said plate to said cast metal structure, the outer surface of which constitutes the desired heating surface. n

2. In an electric heater, in combination, a resistor, a supporting elenent therefor of good heat-conducting properties, means for securing said resistor to a surface of said supporting element and for insulating it therefrom, and a second element to which said supporting element is integrally united by its other surfaces, said second element having a surface constituting the working face of the heater, the heatfrom the resistor being conducted to said second element through said first heat-conducting element.

3. In a heater structure, in combination, a resistor, a supporting element therefor of good heat conductivity, means for securing said resistor to one side of said heat conducting element and for insulating it therefrom, and a second element formed of metal cast against the opposite side vof said heatconducting element, the outer surface of said second element constituting the Working face, whereby said resistor is structurally independent of said element.

4. In an electric heater, a plate of good heat-conducting properties, a resistor carrier engagingthe same, and a cast metal plate partially embracing said first plate and serving to secure said carrier permanently in position whereby said resistor may be installed and replaced independently of said cast metal plate, said cast plate having a working surface to which heat is readily conducted through said first plate.

5. In an electric heater, a plate of good heat-conducting properties, a resistor carrier engaging the same, a cast 'metal plate partially embracing said plate and serving to secure said carrier permanently in position, said' cast plate having a working surface to which heat is readily conducted through said first plate, and a resistor setherefrom, a sheet metal carrier for each plate, each carrier being secured to a plate and serving to secure said resistor in close heat-conducting relation therewith, and a common supporting structure cast about said plates.

8. In an electric heater, a steel plate having a smooth finished surface, a cast iron structure cast partially about one side of said steel plate, said cast iron having a smooth working face, a resistor, and sheet metal elements secured in said cast metal and bent over said resistor to compress the same against the smooth surface of said steel plate.

9. An electric heater comprising a cast iron shoe having the outline of a laundry iron, a rolled steel plate embedded therein and having an opening therethrough, sheet metal strips secured between said steel plate and said cast iron and held firmly in position due to the shrinkage of the iron in casting, a resistor held against said steel plate by said sheet metal strips and insulated therefrom, and means for securing the upper parts of the iron to said shoe, said means being received within said opening and being embedded in said cast iron.

In witness whereof, I have hereunto subscribed my name in the presence of two witnesses.

WILLIAM S. IIADAWAY, JR. Witnesses:

R. R. KNAPP, A. HAGEN. 

